Recently, with activation of financial transactions, including electronic payment using mobile terminals, such as smart phones and tablet personal computers (tablet PCs), security issues, including passwords, are garnering a large amount of interest.
This is because, in the case of smart phones, different from the existing mobile phones, applications are able to be developed by anyone and the structure is known to everyone, thus having a vulnerability to hacking, similar to PCs that are widely used.
In particular, when a password or resident registration number is input using a fixed keypad, the password or resident registration number may be easily obtained only by finding out a position being touched for the input, and thus users should be cautious in inputting passwords.
A method for compensating for the limitation in using a fixed keypad includes an authentication method using a variable keypad. The variable keypad method operates in such a way that the arrangement of input buttons of the keypad is changed whenever a user uses the variable keypad, so that even when a third party finds out the positions of a password and the like that are input by the user to the keypad, it is not easy for the third party to find out the password using the positions.
However, even in the use of the variable keypad, when the scene of inputting the password is observed, or the password and the like are hacked in the middle of transmission from a mobile terminal to a server at a time of an authentication request, the password itself is subject to discovery, thus there is a limitation in the security against personal information leaks.
In addition, it is also difficult to prevent a third party from performing identity authentication by using the password obtained as described above and deceiving identity.